hdf5

[svn-r23825] Bug HDFFV-8469: C++ comments in C code.
Found and removed two more "//" comments.

Tested: in Koala by
$ env CFLAGS="-ansi" ../hdf5/bin/buildhdf5 -fortran -cxx -config # enable fortran and cxx, configure only
$ make AM_CFLAGS=-ansi # compile all source file by setting HDF5 build CFLAGS as "-ansi" only